This website requires Javascript for some parts to function propertly. Your experience may vary.

GB-250-B (new)


Hydromechanical Grease Interceptor

Alternate Configuration


Online: $5,472.60

List: $7,818.00

Buy Now

75 GPM / 1,560 lbs at 99%

Indoor / Outdoor

277 GAL

Liquid Capacity

Intended Market: Miami DERM

Satisfies Miami DERM 99% efficiency requirements. Learn more about our solutions for this region. Also approved in jurisdictions where a baffle is required.

Product Description

99% Efficient, 75 GPM Hydromechanical Grease Interceptor

Released September 2023, The NEW GB-250-B uses the same patented barrel-style baffle that we already use with the GB-75-B. Furthermore, the new-style GB-250-B only requires one PP3 pumpout port, as opposed to two with the legacy version. Please use this style on all plans moving forward, as the legacy model will retire at the end of 2024.

The GB-250-B offers best-in-class certified grease capacity and can be installed above grade (on the ground) or buried below grade (compatible with FCR2 risers to bring system to grade), as well as indoor or outdoor. The triple outlet features allow for installation flexibility, including the ability to connect an unused inlet/outlet for remote pumpout (PP3 compatibility - this unit requires quantity of 1).

More Features:

  • Rugged polyethylene tank body

  • No flow control required, first in the industry certified to Type D of the ASME standard

  • Safety Star® access restrictor prevents accidental entry

  • Fits through 36" doorways

  • Contains a barrel-style baffle

Listed by IAPMO to ASME A112.14.3 and CSA B481.1.

Alternate Configurations

GB-250 — 100/200 GPM, 277-gallon grease interceptor

GB-250-250HF — 250 GPM, 277-gallon grease interceptor intended for Vancouver, British Columbia market

Need Documentation?

Technical Information

Flow Rate/Grease Capacity
75 GPM (4.7 L/s) / 1,560 lbs (707.5 kg) at 99%

Solids Capacity 55 gal (208.2 L)

Liquid Capacity 277 gal (1,048.6 L)

Weight 390 lbs (176.9 kg)

Installation Location Indoor/Outdoor

GB-250-B product image

on-grade perfection

Schier's cover adapters give 4" of vertical adjustability and up to a 5-degree tilt in any direction, helping to ensure covers are installed perfectly inline on the concrete pad.



Three outlets available for installation flexibility and optional pumpout port connection.

on the tank

Product ID label with technical and certification details (also available inside the cover adapter)

In-series label that shows grease capacity for in-series installations

"Made By" label featuring one of our product builders and the date your interceptor was built

Schier Flow Technology™


Water, grease and solids enter a grease interceptor through an inlet diffuser moving toward the bottom of the tank. The mixture first meets the diffuser foot, which increases cross sectional area and slows the velocity of flow entering the tank. The mixture hits the inlet wall, forcing water and grease to flow upward creating a floating grease layer, while solids sink and settle in the bottom. The dissipation aids in the creation of laminar flow, allowing time for grease and water to separate as they move across the tank. The outlet diffuser draws clean water from the bottom of the tank and delivers it into the downstream flow.


Riser Options

Schier's FCR2 field cut risers are designed for easy modification in the field to reduce jobsite installation time and eliminate custom riser costs.

If using 24" corrugated risers (by others), you will need the CA2 riser adapters. You will not use a CA2 with an FCR2.



FCR2 product image
Riser for grease interceptors with 24" covers installed below grade.
PP3 product image
Pumpout Port Kit that converts an outlet into a pumpout port. Use with GB-50, GB-75, GB-250, GB-500.
AK1 product image
This anchor kit is recommended for installation in high water table conditions to prevent float out.
AGS1 product image
Above grade support kit for use with the GB-250 in suspended installations only.
ATD1 product image
For securing covers to units in ABOVE GRADE INSTALLATIONS with increased head pressure conditions.
CA2 product image
Adapter for 24" Corrugated Pipe Riser
CC2 product image
For recessed and suspended units with 24" covers.
PLAIN-EA-24 product image
4" MPT - 2" Plain End Fitting.
PLAIN-EA-34 product image
4" MPT - 3" Plain End Fitting.
FPT-EA-23 product image
3" MPT - 2" FPT Fitting.
FPT-EA-34 product image
4" MPT - 3" FPT Fitting.

Frequently Asked Questions

Are the Great Basin® indoor/outdoor units traffic rated (H-20 load rate)?

These units are traffic rated if they are installed in accordance with our installation instructions. The unit will need the H-20 load-rated cast iron covers and a traffic-rated pad at grade per our installation detail.

Can corrugated pipe be used as a riser on the Great Basin® indoor/outdoor units?

A 24" double wall corrugated pipe can be used as a riser for these units. You will need to purchase Schier's adapter for 24" corrugated pipe riser (CA2).

Can the discharge from a food waste grinder be run through the Great Basin® indoor/outdoor units?

These units have solids capacity of 20% or more of the unit's liquid volume, but food waste grinders can quickly overwhelm a grease interceptor. If the food waste grinder is connected to the unit, we recommend a solids interceptor in front of the grease interceptor.

Can the Great Basin® indoor/outdoor units be installed above grade (on the ground)?

All Great Basin® indoor/outdoor models can be installed above grade. The the adapter tie down kit (ATD1) is recommended to ensure the adapters do not become unseated in the event of a downstream backup. A GB-500 installed above grade must also have the above grade support kit (AGS2).

Can the Great Basin® units be used with a dishwasher?

These units can be used with a dishwasher. If the dishwasher will have a discharge temperature higher than 150 degrees Fahrenheit, the system will require a drain tempering valve to reduce the water temperature.

Can you suspend the Great Basin™ indoor/outdoor units from the ceiling above?

These units can be suspended from above (with the exception of GB-1000 and GB-1500). The unit needs to be fully supported across the bottom with risers extending to the floor above. It is the responsibility of the specifying engineer or installer to design a support system appropriate for the weight of the unit with water. If suspending a GB-250, the unit must be installed with the above grade support kit (AGS1). If suspending a GB-500, the unit must be installed with the above grade support kit (AGS2).

Do the Great Basin™ indoor/outdoor units need to be installed inside a vault to be buried in a high-water table area?

If the units will be installed in an area where the water table will crest the inlet/outlet pipe, additional steps need to be taken to protect the unit from the extreme hydrostatic forces. The unit would need to be placed in a water tight vault or encased in concrete. If there is a possibility that ground water will come into contact with the unit, there needs to be a high-water/anti-flotation anchor kit installed (AK1, AK2, AK3).

Do the Great Basin® units require a fixture vent?

These units do not require a fixture vent. The internal design of the unit will ensure proper function without a fixture vent. Any venting to the piping connected to our unit is at the discretion of the local authority.

How much space is needed between units when they are installed in series?

There should be a minimum of 6" between the units when installed in series. In a buried application, this space will ensure there is enough backfill in between the units.

Our fixture has an air gap and discharges into a floor sink, which is overflowing. How can we fix this?

Due to the low head pressure in this scenario, the first solution is to remove the internal flow control. This low head pressure ensures the unit will not exceed its certified flow rate. If that doesn’t solve the issue, the next solution is to add a flow restrictor to the tailpiece of the fixture.

What are the minimum and maximum riser heights of buried Great Basin™ indoor/outdoor units?

The adjustable adapters that ship with these units offer up to 4" of built-in riser height. The maximum height for field cut risers is 94," which is equivalent to three FCR2 risers (sold separately). If the unit is suspended with risers to the floor above, they can use more than three if needed.

Scroll To Top